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Saturday, August 15, 2015

Lines I Wished I’d Written: How the Cat Works

I have not been reading much this whole summer. I’ve gotten lazy and the evenings are taken
up with following baseball, my sports love.
But I have been reading the ASPCA
Complete Guide to Cats, and found an interesting and well written chapter
titled, “How the Cat Works.” I’ll post
some parts of the chapter, subsection’s title which I put in bold.

How
the Cat Works

In the words of Leonardo
da Vinci, “the smallest feline is a masterpiece.” The cat is one of nature’s most elegant
examples of form following function. The
design of the feline physique is perfectly suited to a predatory carnivore’s
needs: detecting, pursuing, catching, killing, eating, and digesting prey. In fact, the cat’s basic form has changed
relatively little since wildcats first appeared some 30 million years ago. The many species that now inhabit the world’s
jungles forests, deserts, couches, and armchairs all follow the same basic
blueprint. Although most domestic shorthairs
aren’t likely to catch anything more exotic than a few extra hours of sleep,
today’s pet cat is built very much like its wild relatives.

Framework:
Bones and Muscles

As any cat owner knows
simply by watching, the cat is built for grace, flexibility, and power. From a sitting start, it can jump up to nine
times its own height. It can make its
chest and shoulders narrower, to squeeze through almost impossible tight
spaces. It can sleep curled into the
shape of a letter O and, immediately upon awakening, stretch and form an
inverted C, pressing the chest almost to the floor.

Sinuous
Spine

Where does the cat get
its remarkable elasticity, both in motion and at rest? The first place to look is the animal’s
spine. Because cats’ vertebrae are
flexibly connected and have particularly elastic cushioning disks between them,
the feline spine is extremely supple. A
cat’s ability to right itself in midair so that it can land on its feet and to
make rapid changes in direction while pursuing or capturing prey are both made
possible by the flexibility of its spine.

The flexibility of the
cat’s spine also contributes to its fluidity and speed as a runner. To reach top speed—about thirty miles an
hour—a domestic cat depends on its spine as much as its feet and leg
muscles. When running, cats can lengthen
their stride, and thus increase their speed, by alternately extending and
flexing their vertical column. When the
cat’s feet push off to start a new stride—the claws serving as spikes for
traction—the cat’s body stretches to its maximum length. The cat’s running style thus resembles a
series of elongated jumps or bounds. The
cat increases its speed by lengthening its stride with each bound, until every
stride carries it about three times the length of its own body. Many other mammals, especially humans, rely
on a more pistonlike sprinting style, in which the key factor is how often the
feet make contact with the ground.

Stretching
and Squeezing

Another special feature
that contributes to feline flexibility is the tiny, rudimentary collarbone,
which helps cats lengthen their stride when sprinting by allowing them to
extend their forelegs fully. The lack of
a long, anchored collarbone (as humans have) gives cats the ability to squeeze
through tight openings by literally compressing themselves to fit the available
space. Moreover, the feline shoulder
blade is attached to the rest of the body only by muscles, not bone. This gives the shoulder blade tremendous
freedom to move as the cat moves, enhancing the cat’s flexibility and grace and
extending its long running stride.

Legs
and Toes

Whether running or
walking, cats land on their toes. Such
digitigrade locomotion is the hallmark of a sprinter. Animals that land on their full soles of
their feet, using plantigrade locomotion, are better suited to sustain
exertion. Bears and humans, for example,
have a plantigrade footfall. Cats hunt
using great bursts of speed (after which they often end up panting).

The spring in a cat’s
legs is phenomenal, thanks in part to the construction of its hip, knee, and
ankle joints. These joints have very
little give from side to side. They are
very stable and strong and can withstand great force applied in one direction:
forward. When the cat’s hind leg muscles
contract, the three joints extend in an instant, giving the animal enormous
thrust to carry it either high or far.
The cat’s landing is cushioned by the thick pads on its feet, and by the
bones of its feet and wrists, whose intricate construction makes a stable
two-point landing on its forepaws possible.

Explosive
Power

One look at a cat in
profiler provides an obvious clue as to why cats are such marvelous, explosive
athletes. In proportion to its overall
body size, a cat’s hindleg muscles are enormous, as is its “launching pad,” an
exceptionally long rear foot. These
anatomical features translate into tremendous power and mechanical advantage
when a cat springs or leaps.

The cat’s particular type
of athleticism may also come partly from many “fast-twitch-fatiguing” cells
contained in its skeletal muscles. As
their names suggest, these cells produce explosive movement, but they use up
their energy stores in a flash and tire easily—as does the cat, which has
relatively few “slow-twitch” fibers to give it endurance.

Energy
Conservation

Because cats lack the
staying power of plantigrade long-distance runners, conserving energy is a must
for them. Even the way a cat walks can
save energy, as the contralateral gait cats sometimes use—left hindfoot moving
more or less in tandem with the right forefoot, and right hindfoot moving with
the left forefoot—is mechanically very efficient.

The best energy-saving
strategy, of course, is to stay put, and cats are masters at it. Their brain chemistry makes it possible for
them to spend more of their time asleep than awak.

Lightning
Fast Nerves

When cats are awake, an
intricate network of nerves radiating from the brain and the spinal cord
operates in high gear, receiving and transmitting information and governing
sensations, reflexes, and motor functions throughout the cat’s body. The lightning speed at which the cat’s
nervous system operates is illustrated by the well-known feline “righting
reflex.” Thanks to this and its
remarkable flexible spine, a cat held feet upward and dropped will have its
feet pointed downward, ready to land, before it has fallen twenty-four inches.

Dexterity

A cat’s wrist bones and
their associated tendons and ligaments give the cat a measure of manual
dexterity—not close to matching our own, or even a raccoon’s but enough to
enable the cat to get mice out of hiding places (or food out its dish) with a
handlike scooping motion and to hold onto trees. This ability to pronate the wrist
(carpus)—turn the bottom of the paw toward the midline of the body—is not
common in the animal kingdom. But then,
neither are most creatures as graceful and nimble, yet powerful, as cats.

That’s enough for now.
Isn’t that fascinating? It
reminds me of an engineering project, only thing God being the engineer.

Let me end this with a recent picture of Tiger, here
sitting on the windowsill. That sill is
a good three feet off the ground and he makes a smooth calculated leap onto
that less than two inch ledge.

Isn't he a handsome kitten? He's four months old now, and that picture was snapped three weeks ago. I had to put a stop to him going on that ledge. Early one morning, while the birds were
chirping out there in the trees, he climbed up the window screen to the
top. It’s a good thing the screen didn’t
fall out.